PURPOSE: This study evaluated the result of fixation of unstable intertrochanteric fractures using an anti-hypersliding compressive hip screw and a trochanter stabilizing plate. MATERIALS AND METHODS: One hundred patients with unstable intertrochanteric fractures who were given an anti-hypersliding compressive hip screw (Group A) or conventional compressive hip screw (Group B) were analyzed. The mean follow-up period was 23.5 months. Radiographic evaluation included the changes of neck-shaft angle, lateral displacement of proximal fragment, distal migration of the lag screw, fixation failure, and union time using plain radiographs taken at postoperative and last follow-up time. RESULTS: Lateral displacement of the proximal fragment averaged 1.62 mm in Group A and 3.97 mm in Group B, which was statistically significant (p<0.05). The neck-shaft angle was increased in Group B, but has no significance. The average of the Harris hip score and walking ability after surgery is higher in Group A than B, but there was no significant difference. The complication rate was significantly lower in Group A. But union time showed no difference in each group. CONCLUSION: Anti-hypersliding compression hip screw with a TSP, which reduces sliding of the lag screw and extreme change of the moment arm, is a another good option for the treatment of intertrochanteric femoral fractures against an increase of the failure rate from the hypersliding of the lag screw.